Apps for the iPads in grades k1-grade2:


ShowMe
KeyNote
Pages

This one isn't on the image yet, but it's easy to get: ComicLife

Online publishing sites for young children:

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Kids' Space Storybook offers a variety of options for publishing kids' works in grades 2–8. Kids can contribute to a monthly pictograph story, write their own original stories, help write an original story as a class project, create a pictograph to illustrate someone else's story, or write a story for someone else's picture.
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The Kids' Storytelling Club presents monthly a new story theme for primary grade kids. The site includes crafts and activities to use with their stories.
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This British-based website provides an interactive tool for creating stories, as well as links to other sites in the United Kingdom where the writing of younger students can be published.
Little Planet Times external image dkgrey_white_10px.png

Little Planet Times is an online newspaper by kids and for kids grades K–5. Youngsters can enjoy other kids' creative stuff and submit letters, stories, jokes, movie and book reviews, or whatever else they would like.
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The mission of CyberKids is to provide a voice for young people on the Internet by publishing original creative work by kids aged 7 to 12.
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Launch Pad provides a creative and engaging atmosphere for young writers and artists to display their work. It also provides tips and ideas to help kids improve on their writing.

...and finally I thing a wonderful place for anyone to publish is on a class blog. Easy feedback, easy to use and share, easy to monitor or restrict access.